Effect of Thermal Rayleigh and Lewis Numbers on Double-Diffusive Natural Concection in a Closed Annulus

A numerical study for steady laminar double-diffusive natural convection within a vertical closed circular annulus is examined with a constant temperature and mass species (concentration) difference imposed across the vertical walls. The effects of thermal Rayleigh number (5000 ≤ Ra T ≤ 100,000) and Lewis number (1 ≤ Le ≤ 10) are investigated for buoyancy ratios of −2, − 1.2, − 1, and 2, representing conditions for mass species dominated …